Project Summary The goal of this Shared Instrumentation Grant application is to provide photoacoustic imaging to the Penn State Hershey Medical Center research community. Photoacoustic imaging is an optical technique that converts incident excitation light into acoustic waves?it has the contrast and spectral behavior of optics with the spatial/temporal resolution and depth penetration of ultrasound. No similar instrumentation is available in Hershey and upgrading and expanding the ultrasound/photoacoustic imaging capabilities will have a profound impact on many areas of research. More specifically, we propose to acquire an MSOT iThera inVision 512-Echo device, which is a dedicated small animal photoacoustic scanner. The iThera platform is the only photoacoustic scanner based on an arc detector array as opposed to a linear detector array, which allows for greater spatial resolution and more detector elements than competitors, but at the same price point as competing photoacoustic scanners. This allows us to do whole-body live mouse imaging with real-time quantitative analysis. Photoacoustic imaging devices can image anatomic structures (tumor size) while collecting functional information (hemoglobin/deoxyhemoglobin, melanin), physiological information (Pharmokinetic perfusion modeling), and molecular-level information (contrast agents for vascular and extracellular targets). Our user base (10 major users; 2 minor users; 12 NIH funded grants) has developed a very powerful portfolio of optical imaging probes and adding photoacoustic capabilities to our campus will offer increased spatial and temporal resolution and up to three additional centimeters of depth penetration. This is critical for fundamental studies into the tumor microenvironment, cancer metastasis, and tumor resection as well as basic studies of drug delivery vehicles. This system also has a broad portfolio of tools to process data and analyze probe Pharmokinetics. We believe that this dedicated pre-clinical scanner will ultimately have a powerful impact on human disease including screening, staging, treatments, and monitoring response to therapy. Penn State Hershey Medical Center offers institutional support, including a dedicated small animal imaging facility as well as matching funds. The studies we are proposing?and have already received NIH funding to perform?nicely match the public health goals established by the NIH and Penn State Hershey Medical Center. This equipment will not only increase the findings achievable with our existing NIH funding, but will also enable multiple new studies in the fields of cancer, cardiology, inflammation, and neurology.